Only just realized this when watching a diving video.
But why isn’t the ocean full of massive plants? The surface of the earth is covered is giant trees working to fight against gravity, wind, and fire.
But in the ocean you have little things like coral beds and sponges and maybe a kelp forest.
Seeing as weight is massively reduced, and the closer you get to the surface means more light, and water and nutrients are probably plentiful… Why isn’t the plant life more massive? What is the limiting factor to things evolving to be bigger?
Only thing I can think of is CO2 perhaps?
From what I searched, cellulose from kelp is different from cellulose from trees, from a properties perspective, so it seems it only acts this way on land is because it’s on land. Maybe the need for a stronger material built trees for them to be the way they are, not having a need for a strong trunk can make an inpact on the evolutionary path of those beings.
It could be that the environment primed trees to need this structure, while ocean beings never experienced the evolutionary force to build some structures in the same way.
Idk, I’m not a biologist.
Edit: So the chemical and physical environment not encouraging the evolutions teps needed for trees to form in the ocean.